Assisting return to a first network from a second network after performance of a circuit switched fallback procedure

ABSTRACT

A method for assisting a wireless communication device to return to a first network from a second network is provided. The method can include the wireless communication device participating in a CSFB procedure to transition from the first network to the second network for servicing of a voice call; receiving a connection release from the second network after termination of the voice call; initiating a reselection procedure to reselect to the first network; determining presence of packet switched data ready for transmission from the wireless communication device before completion of the reselection procedure; holding the packet switched data at the wireless communication device at least until expiry of a reselection timer initiated during the reselection procedure; reselecting to the first network after expiry of the reselection timer; and initiating transmission of the packet switched data on the first network after completing reselection to the first network.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/783,075, filed on Mar. 1, 2013, the disclosure of which isincorporated herein by reference in its entirety.

FIELD OF THE DESCRIBED EMBODIMENTS

The described embodiments relate generally to wireless communicationsand more particularly to assisting return to a first network from asecond network after performance of a circuit switched fallback (CSFB)procedure.

BACKGROUND

Cellular networks using newer radio access technology (RAT) systems,such as Long Term Evolution (LTE) systems, are being developed anddeployed. Networks using these newer RATs often support faster datarates than networks utilizing legacy RATs, such as second generation(2G) and third generation (3G) RATs, including Universal MobileTelecommunications System (UMTS) networks and Global System for MobileCommunications (GSM) networks. However, in some deployments, LTE andother new RATs may not fully support some services that can be handledby legacy networks. Accordingly, LTE networks are often co-deployed inoverlapping regions with legacy networks and wireless communicationdevices may transition between RATs as services or coverage may require.For example, in some deployments, LTE networks are not capable ofsupporting voice calls. Accordingly, when a wireless communicationdevice receives or initiates a voice call while connected to a networkthat supports data sessions, but not voice calls, the wirelesscommunication device can perform a circuit switched fallback (CSFB)procedure to transition to a legacy network that supports voice calls.

In some instances, there may be a significant amount of background datatraffic on a wireless communication device, including, for example,email, a data service for keeping a device connected to servers, and/orthe like. Since newer networks, such as LTE, can offer faster data ratesthan legacy networks, devices enabled to operate on LTE networksgenerally prefer to stay on LTE when LTE access is available for bothidle state and active data transmission state. In this regard, LTE canoffer a better user experience than legacy networks due to its higherdata rates. Under the CSFB scheme, LTE will only provide the dataservice, while legacy networks will provide both voice and data service.Due to the nature of smart phones and other wireless communicationdevices, data traffic can be serviced at the same time with the voicecall on a legacy network. However, even after the voice call hasterminated, a wireless communication device can sometimes be inhibitedfrom returning to LTE due to underlying data traffic activities, as adevice can need idle time to do system re-selection in order for it toreturn to LTE. Even when a wireless communication device has idle timeto complete a reselection to LTE, data packets can often arrive at abaseband layer of the device from higher layers for transmission to thenetwork, and the device can abort the reselection procedure and remainon the legacy network to transmit the data. In this regard, currentwireless communication devices can discard timers tied to cellreselection and remain on a legacy network in response to data packetsarriving at the baseband layer for transmission before a reselectionprocedure has been completed. The reselection procedure can then berestarted after completion of the data transfer. As such, even thoughwireless communication devices generally prefer to operate on LTEnetworks when available unless servicing an active voice call in orderto provide better user experience, a device can often be stuck on alegacy network even after termination of a voice call if there is anactive data transfer, or if data packets become ready for transmissionbefore reselection is completed. Users can accordingly experience lessthan desirable data performance for significant time periods followingvoice call termination even when access to a network offering fasterdata rates is available.

SUMMARY OF THE DESCRIBED EMBODIMENTS

Some example embodiments disclosed herein provide for assisting returnto a first network from a second network after performance of a CSFBprocedure. In this regard, a wireless communication device in accordancewith some example embodiments can be configured, in the event thatpacket switched data is ready for transmission from the device prior tocompletion of a reselection procedure, to hold the packet switched dataat least until expiry of a reselection timer that can be initiatedduring the reselection procedure. Holding the packet switched data inaccordance with such example embodiments can allow for completion of thereselection procedure so that transmission of the packet switched datacan be initiated on the first network after reselection has beencompleted. In embodiments in which the first network can offer fasterdata rates than the second network, such as in embodiments in which thefirst network is an LTE network and the second network is a legacynetwork, user experience can accordingly be improved, as allowing forcompletion of the reselection procedure before initiating the datatransfer can provide faster data rates for the data. In most instances,the time for which the packet switched data can be held to allow forcompletion of the reselection procedure before initiating datatransmission can be insignificant in comparison to the reduction in theamount of time that it can take to transfer the data on the firstnetwork versus the second network. As such, user experience can benoticeably improved in spite of the delay in initiating datatransmission in most instances.

In a first embodiment, a method for assisting a wireless communicationdevice to return to an LTE network from a legacy network is provided.The method of the first embodiment can include the wirelesscommunication device participating in a CSFB procedure to transition thewireless communication device from the LTE network to a legacy networkfor servicing of a voice call. The legacy network can have a circuitswitched domain and the voice call can be handled by the circuitswitched domain of the legacy network. The method of the firstembodiment can further include the wireless communication devicereceiving a connection release from the legacy network after terminationof the voice call; initiating a reselection procedure to reselect to theLTE network; determining presence of packet switched data ready fortransmission from the wireless communication device before completion ofthe reselection procedure; holding the packet switched data at thewireless communication device at least until expiry of a reselectiontimer initiated during the reselection procedure; reselecting to the LTEnetwork after expiry of the reselection timer; and initiatingtransmission of the packet switched data on the LTE network aftercompleting reselection to the LTE network.

In a second embodiment, a method for assisting a wireless communicationdevice to return to a first network from a second network is provided.The method of the second embodiment can include the wirelesscommunication device participating in a CSFB procedure to transition thewireless communication device from the first network to the secondnetwork for servicing of a voice call; receiving a connection releasefrom the second network after termination of the voice call; initiatinga reselection procedure to reselect to the first network; determiningpresence of packet switched data ready for transmission from thewireless communication device before completion of the reselectionprocedure; holding the packet switched data at the wirelesscommunication device at least until expiry of a reselection timerinitiated during the reselection procedure; reselecting to the firstnetwork after expiry of the reselection timer; and initiatingtransmission of the packet switched data on the first network aftercompleting reselection to the first network.

In a third embodiment, a wireless communication device is provided. Thewireless communication device of the second embodiment can include atleast one transceiver and processing circuitry coupled to the at leastone transceiver. The at least one transceiver can be configured totransmit data to and receive data from a first network and a secondnetwork. The processing circuitry can be configured to control thewireless communication device to at least participate in a CSFBprocedure to transition from the first network to the second network inresponse to initiation of a voice call; receive a connection releasefrom the second network after termination of the voice call; initiate areselection procedure to reselect to the first network; determinepresence of packet switched data ready for transmission from thewireless communication device before completion of the reselectionprocedure; hold the packet switched data at the wireless communicationdevice at least until expiry of a reselection timer initiated during thereselection procedure; reselect to the first network after expiry of thereselection timer; and initiate transmission of the packet switched dataon the first network after completing reselection to the first network.

In a fourth embodiment, a computer program product for assisting awireless communication device to return to a first network from a secondnetwork is provided. The computer program product of the fourthembodiment can include at least one non-transitory computer readablestorage medium having program code stored thereon. The program code caninclude program code for participating in a CSFB procedure to transitionthe wireless communication device from the first network to the secondnetwork for servicing of a voice call; program code for receiving aconnection release from the second network after termination of thevoice call; program code for initiating a reselection procedure toreselect to the first network; program code for determining presence ofpacket switched data ready for transmission from the wirelesscommunication device before completion of the reselection procedure;program code for holding the packet switched data at the wirelesscommunication device at least until expiry of a reselection timerinitiated during the reselection procedure; program code for reselectingto the first network after expiry of the reselection timer; and programcode for initiating transmission of the packet switched data on thefirst network after completing reselection to the first network.

In a fifth embodiment, an apparatus for assisting a wirelesscommunication device to return to a first network from a second networkis provided. The apparatus of the fifth embodiment can include means forparticipating in a Circuit Switched Fallback (CSFB) procedure totransition the wireless communication device from the first network tothe second network for servicing of a voice call; means for receiving aconnection release from the second network after termination of thevoice call; means for initiating a reselection procedure to reselect tothe first network; means for determining presence of packet switcheddata ready for transmission from the wireless communication devicebefore completion of the reselection procedure; means for holding thepacket switched data at the wireless communication device at least untilexpiry of a reselection timer initiated during the reselectionprocedure; means for reselecting to the first network after expiry ofthe reselection timer; and means for initiating transmission of thepacket switched data on the first network after completing reselectionto the first network.

The above summary is provided merely for purposes of summarizing someexample embodiments of the invention so as to provide a basicunderstanding of some aspects of the invention. Accordingly, it will beappreciated that the above described example embodiments are merelyexamples and should not be construed to narrow the scope or spirit ofthe invention in any way. Other embodiments, aspects, and advantages ofthe invention will become apparent from the following detaileddescription taken in conjunction with the accompanying drawings whichillustrate, by way of example, the principles of the describedembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The described embodiments and the advantages thereof may best beunderstood by reference to the following description taken inconjunction with the accompanying drawings. These drawings are notnecessarily drawn to scale, and in no way limit any changes in form anddetail that may be made to the described embodiments by one skilled inthe art without departing from the spirit and scope of the describedembodiments.

FIG. 1 illustrates overlapping coverage of a fourth generation networkand a legacy network in accordance with some example embodiments.

FIG. 2 illustrates an example system having multiple wirelesscommunication networks to which a wireless communication device canconnect in accordance with some example embodiments.

FIG. 3 illustrates a block diagram of an apparatus that can beimplemented on a wireless communication device in accordance with someexample embodiments.

FIG. 4 illustrates a flowchart according to an example method forassisting return to a first network from a legacy network afterperformance of a CSFB procedure according to some example embodiments.

FIG. 5 illustrates a flowchart according to another example method forassisting return to a first network from a legacy network afterperformance of a CSFB procedure according to some example embodiments.

FIG. 6 illustrates a flowchart according to an example method forassisting return to a first network from a legacy network afterperformance of a CSFB procedure by holding packet switched data at leastuntil expiry of a reselection timer applied for determining whether atarget cell of the first network is better than the serving cell of thelegacy network according to some example embodiments.

FIG. 7 illustrates a flowchart according to an example method forassisting return to an LTE network from a legacy network afterperformance of a CSFB procedure according to some example embodiments.

FIG. 8 illustrates a flowchart according to an example method forassisting return to a first network from a legacy network afterperformance of a CSFB procedure by holding packet switched data at leastuntil expiry of a reselection timer applied to allow measurement of adetected cell of the first network according to some exampleembodiments.

FIG. 9 illustrates a flowchart according to an example method forassisting return to an LTE network from a legacy network afterperformance of a CSFB procedure according to some example embodiments.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

Representative applications of methods and apparatus according to thepresent specification are described in this section. These examples arebeing provided solely to add context and aid in the understanding of thedescribed embodiments. It will thus be apparent to one skilled in theart that the described embodiments may be practiced without some or allof these specific details. In other instances, well known process stepshave not been described in detail in order to avoid unnecessarilyobscuring the described embodiments. Other applications are possible,such that the following examples should not be taken as limiting.

In the following detailed description, references are made to theaccompanying drawings, which form a part of the description and in whichare shown, by way of illustration, specific embodiments in accordancewith the described embodiments. Although these embodiments are describedin sufficient detail to enable one skilled in the art to practice thedescribed embodiments, it is understood that these examples are notlimiting; such that other embodiments may be used, and changes may bemade without departing from the spirit and scope of the describedembodiments.

Some example embodiments disclosed herein provide for assisting returnto a first network from a second network after performance of a CSFBprocedure. In this regard, some example embodiments address a situationin which packet switched data can become ready for transmission from awireless communication device before the device has completed areselection procedure for reselecting to the first network. Moreparticularly, a wireless communication device in accordance with someexample embodiments can be configured, in the event that packet switcheddata is ready for transmission from the device prior to completion of areselection procedure, to hold the packet switched data at least untilexpiry of a reselection timer that can be initiated during thereselection procedure. Holding the packet switched data in accordancewith such example embodiments can allow for completion of thereselection procedure so that transmission of the packet switched datacan be initiated on the first network after reselection has beencompleted.

In embodiments in which the first network can offer faster data ratesthan the second network, such as in embodiments in which the firstnetwork is an LTE network and the second network is a legacy network,user experience can accordingly be improved, as allowing for completionof the reselection procedure before initiating the data transfer canprovide faster data rates for the data transfer. In most instances, thetime for which the packet switched data can be held to allow forcompletion of the reselection procedure before initiating datatransmission can be insignificant in comparison to the reduction in theamount of time that it can take to transfer the data on the firstnetwork versus the second network. As such, user experience can benoticeably improved in spite of the delay in initiating datatransmission in most instances.

FIG. 1 illustrates overlapping coverage of a fourth generation (4G)network 102 and a legacy network 104 in a communications system 100 inaccordance with some example embodiments. The 4G network 102 can, forexample, be a network using an LTE technology, such as an LTE network orLTE-Advanced (LTE-A) network, or other network that can offer fasterdata rates than legacy networks, such as second generation (2G) andthird generation (3G) networks, but may not support voice calls. It willbe appreciated that the 4G network is illustrated by way of example, andnot by way of limitation. In this regard, other networks in existencenow or that may be developed in the future that can offer higher datarates than legacy networks, but which do not support circuit switched(CS) voice calls can be substituted for the 4G network 102 within thescope of the disclosure. The legacy network 104 can be any legacynetwork having a CS domain to support CS voice calls. By way ofnon-limiting example, the legacy network 104 can be a 3G network, suchas a Wideband Code Division Multiple Access (WCDMA) or other UniversalMobile Telecommunications System (UMTS) network, such as a Time DivisionSynchronous Code Division Multiple Access (TD-SCDMA) network. As afurther example, the legacy network 104 can be a CDMA2000 network, suchas a 1xRTT network, or other network standardized by the ThirdGeneration Partnership Project 2 (3GPP2) that supports a CS domain. Asanother example, the legacy network can be a 2G network such as a GlobalSystem for Mobile Communications (GSM) network.

The 4G network 102 and legacy network 104 can each have regions ofcoverage represented by the respective circles illustrated in FIG. 1.The regions of coverage can overlap, such as illustrated by theoverlapping portions of the circles in FIG. 1. A wireless communicationdevice in accordance with some example embodiments can operate on boththe 4G network 102 and the legacy network 104. Thus, for example, whenthe wireless communication device is in a region of overlappingcoverage, the wireless communication device can be connected to the 4Gnetwork 102 with an ongoing data session and can perform a CSFBprocedure to the legacy network 104 in response to initiation of a voicecall.

FIG. 2 illustrates an example system 200 having multiple wirelesscommunication networks to which a wireless communication device 202 canconnect in accordance with some example embodiments. By way ofnon-limiting example, the wireless communication device 202 can be acellular phone, such as a smart phone device; a tablet computing device;a laptop computing device; or other computing device configured tooperate within both a first network 204 and a legacy network 206. Thefirst network 204 can be any network supporting packet switched (PS)data sessions, but which does not have a CS domain for supporting CSvoice calls. In some example embodiments, the first network 204 canoffer higher theoretical data rates than the legacy network 206. Thus,for example, the first network 204 can be a network using an LTEtechnology (e.g., an LTE network, LTE-A network, or using anotherpresent or future developed LTE technology) or other 4G network, such asthe 4G network 102 illustrated in FIG. 1. The legacy network 206 can beany network having a CS domain to support CS voice calls. By way ofnon-limiting example, the legacy network 206 can be a UMTS network, a3GPP2 network, or other 3G network. As a further example, the legacynetwork 206 can be a GSM or other 2G network, or other legacy networkthat can support CS voice calls. In this regard, the legacy network 206can be the legacy network 104.

As illustrated in FIG. 2, the wireless communication device 202 can bewithin signaling range of both a base station or other access point forthe first network 204 and a base station or other access point for thelegacy network 206. In this regard, the wireless communication device202 can be located in a region of overlapping coverage of the firstnetwork 204 and the legacy network 206. As such, the wirelesscommunication device 202 can connect to the first network 204. Inresponse to initiation of a CS voice call (e.g., a mobile originatingvoice call initiated by the wireless communication device 202 or amobile terminating voice call placed to the wireless communicationdevice 202), the wireless communication device 202 can participate in aCSFB procedure to transition from the first network 204 to the legacynetwork 206 so that the voice call can be supported. The CSFB procedurecan, for example, be performed as defined in TS 23.272, the contents ofwhich are incorporated herein by reference in its entirety.

FIG. 3 illustrates a block diagram of an apparatus 300 that can beimplemented on a wireless communication device 202 in accordance withsome example embodiments. In this regard, when implemented on acomputing device, such as wireless communication device 202, apparatus300 can enable the computing device to operate within the system 200 inaccordance with one or more example embodiments. It will be appreciatedthat the components, devices or elements illustrated in and describedwith respect to FIG. 3 below may not be mandatory and thus some may beomitted in certain embodiments. Additionally, some embodiments caninclude further or different components, devices or elements beyondthose illustrated in and described with respect to FIG. 3.

In some example embodiments, the apparatus 300 can include processingcircuitry 310 that is configurable to perform actions in accordance withone or more example embodiments disclosed herein. In this regard, theprocessing circuitry 310 can be configured to perform and/or controlperformance of one or more functionalities of the apparatus 300 inaccordance with various example embodiments, and thus can provide meansfor performing functionalities of the apparatus 300 in accordance withvarious example embodiments. The processing circuitry 310 can beconfigured to perform data processing, application execution and/orother processing and management services according to one or moreexample embodiments.

In some embodiments, the apparatus 300 or a portion(s) or component(s)thereof, such as the processing circuitry 310, can include one or morechipsets, which can each include one or more chips. The processingcircuitry 310 and/or one or more further components of the apparatus 300can therefore, in some instances, be configured to implement anembodiment on a chipset(s). In some example embodiments in which one ormore components of the apparatus 300 are embodied as a chipset, thechipset can be capable of enabling a computing device to operate in thesystem 200 when implemented on or otherwise operably coupled to thecomputing device. Thus, for example, one or more components of theapparatus 300 can provide a chipset configured to enable a computingdevice to operate over the first network 204 and/or the legacy network206. In some example embodiments, one or more components of he apparatus300 can provide a cellular baseband chipset, which can enable acomputing device to operate over the first network 204 and/or the legacynetwork 206.

In some example embodiments, the processing circuitry 310 can include aprocessor 312 and, in some embodiments, such as that illustrated in FIG.3, can further include memory 314. The processing circuitry 310 can bein communication with or otherwise control a transceiver(s) 316 and/orselection control module 318.

The processor 312 can be embodied in a variety of forms. For example,the processor 312 can be embodied as various hardware-based processingmeans such as a microprocessor, a coprocessor, a controller or variousother computing or processing devices including integrated circuits suchas, for example, an ASIC (application specific integrated circuit), anFPGA (field programmable gate array), some combination thereof, or thelike. Although illustrated as a single processor, it will be appreciatedthat the processor 312 can comprise a plurality of processors. Theplurality of processors can be in operative communication with eachother and can be collectively configured to perform one or morefunctionalities of the apparatus 300 as described herein. In someexample embodiments, the processor 312 can be configured to executeinstructions that can be stored in the memory 314 or that can beotherwise accessible to the processor 312. As such, whether configuredby hardware or by a combination of hardware and software, the processor312 can be capable of performing operations according to variousembodiments while configured accordingly.

In some example embodiments, the memory 314 can include one or morememory devices. Memory 314 can include fixed and/or removable memorydevices. In some embodiments, the memory 314 can provide anon-transitory computer-readable storage medium that can store computerprogram instructions that can be executed by the processor 312. In thisregard, the memory 314 can be configured to store information, data,applications, instructions and/or the like for enabling the apparatus300 to carry out various functions in accordance with one or moreexample embodiments. In some embodiments, the memory 314 can be incommunication with one or more of the processor 312, transceiver(s) 316,or selection control module 318 via a bus(es) for passing informationamong components of the apparatus 300.

The apparatus 300 can further include transceiver(s) 316. Thetransceiver(s) 316 can enable the apparatus 300 to send wireless signalsto and receive signals from one or more wireless networks, such as thefirst network 204 and the legacy network 206. As such, thetransceiver(s) 316 can be configured to support any type of cellular orother wireless communication technology that may be implemented by thefirst network 204 and/or legacy network 206. In some exampleembodiments, the transceiver(s) 316 can include a single transceiverconfigured to enable the wireless communication device 202 to connect toboth the first network 204 and the legacy network 206. Alternatively, insome example embodiments, the transceiver(s) 316 can include a firsttransceiver configured to enable the wireless communication device 202to connect to the first network 204 and a second transceiver configuredto enable the wireless communication device 202 to connect to the legacynetwork 206.

The apparatus 300 can further include selection control module 318. Theselection control module 318 can be embodied as various means, such ascircuitry, hardware, a computer program product comprising a computerreadable medium (for example, the memory 314) storing computer readableprogram instructions executable by a processing device (for example, theprocessor 312), or some combination thereof. In some embodiments, theprocessor 312 (or the processing circuitry 310) can include, orotherwise control the selection control module 318.

The selection control module 318 can be configured in some exampleembodiments to control performance of a reselection procedure toreselect to the first network 204 from the legacy network 206 aftertermination of a voice call for which a CSFB procedure had beenperformed to transition the wireless communication device 202 from thefirst network 204 to the legacy network 206. In some exampleembodiments, the selection control module 318 can be configured toinitiate the reselection procedure after receiving a connection releasefrom the legacy network 206. After receiving the connection release, thewireless communication device 202 can be in a radio resource control(RRC) state other than cell dedicated channel (CELL_DCH) state, such ascell forward access channel (CELL_FACH) state, cell paging channel(CELL_PCH) state, Universal Terrestrial Access Network (UTRA)registration area paging channel (URA_PCH) state, idle state, or otherstate, which can allow the wireless communication device 202 to reselectto the first network 204.

The selection control module 318 of some example embodiments can beconfigured to determine presence of packet switched (PS) data ready fortransmission from the wireless communication device 202 beforecompletion of the reselection procedure. For example, packet switcheddata can arrive at a cellular baseband layer from a layer higher thanthe cellular baseband layer, such as, by way of non-limiting example, anapplication layer during the reselection procedure. Rather than abortingthe reselection procedure and initiating transmission of the packetswitched data on the legacy network 104 in response to the presence ofthe packet switched data, the selection control module 318 of suchexample embodiments can be configured to hold the packet switched dataat the wireless communication device 202 at least until expiry of areselection timer that can be initiated attendant to performance of thereselection procedure. In this regard, holding the packet switched datat least until expiry of the reselection timer can allow for completionof the reselection procedure so that transmission of the packet switcheddata can be initiated on the first network 204 rather than on the legacynetwork 206.

FIG. 4 illustrates a flowchart according to an example method forassisting return to the first network 204 from the legacy network 206after performance of a CSFB procedure according to some exampleembodiments. In this regard, FIG. 4 illustrates operations that can beperformed by the wireless communication device 202 in accordance withsome example embodiments. One or more of processing circuitry 310,processor 312, memory 314, transceiver(s) 316, or selection controlmodule 318 can, for example, provide means for performing the operationsillustrated in and described with respect to FIG. 4. Operation 400 caninclude the wireless communication device 202 participating in a CSFBprocedure to transition from the first network 204 to the legacy network206 in response to initiation of a voice call. Operation 410 can includethe wireless communication device 202 receiving a connection releasefrom the legacy network 206 after termination of the voice call. Afterreceiving the connection release, the wireless communication device 202can be in an RRC state other than CELL_DCH, such as CELL_FACH, CELL_PCH,URA_PCH, idle state, or other state which can allow the wirelesscommunication device 202 to reselect to the first network 204. Operation420 can include the wireless communication device 202 initiating areselection procedure to reselect to the first network 204.

Operation 430 can include determining presence of packet switched dataready for transmission from the wireless communication device 202 beforecompletion of the reselection procedure. By way of non-limiting example,operation 430 can include determining arrival at a cellular basebandlayer of packet switched data from a higher layer. Operation 440 caninclude holding the packet switched data at the wireless communicationdevice 202 at least until expiry of a reselection timer initiated duringthe reselection procedure. Operation 450 can include the wirelesscommunication device 202 reselecting to the first network 204 afterexpiry of the reselection timer. Operation 460 can include the wirelesscommunication device 202 initiating transmission of the packet switcheddata on the first network 203 after completing reselection to the firstnetwork 204.

In some example embodiments, the reselection timer for which packetswitched data can be held can be applied to allow for measurement and/orother evaluation of a target cell(s) of the first network 204 toevaluate whether reselection criteria is satisfied prior to reselectingto the first network 204. As such, in some example embodiments, if it isdetermined after expiry of the reselection timer that a reselectioncriterion is not satisfied, the reselection procedure can be aborted andtransmission of held packet switched data can be initiated on the legacynetwork 206 rather than completing reselection to the first network 204and initiating transmission of held packet switched data on the firstnetwork 204. If, however, applicable reselection criteria are satisfied,then the reselection to the first network 204 can be completed andtransmission of held packet switched data can be initiated on the firstnetwork 204. FIG. 5 illustrates flowchart according to an example methodfor assisting return to the first network 204 from the legacy network206 after performance of a CSFB procedure according to some such exampleembodiments. In this regard, FIG. 5 illustrates operations that can beperformed by the wireless communication device 202 in accordance withsome example embodiments. One or more of processing circuitry 310,processor 312, memory 314, transceiver(s) 316, or selection controlmodule 318 can, for example, provide means for performing the operationsillustrated in and described with respect to FIG. 5.

Operation 500 can include the wireless communication device 202participating in a CSFB procedure to transition from the first network204 to the legacy network 206 in response to initiation of a voice call.Operation 510 can include the wireless communication device 202receiving a connection release from the legacy network 206 aftertermination of the voice call. After receiving the connection release,the wireless communication device 202 can be in an RRC state other thanCELL_DCH, such as CELL_FACH, CELL_PCH, URA_PCH, idle state, or otherstate which can allow the wireless communication device 202 to reselectto the first network 204. Operation 520 can include the wirelesscommunication device 202 initiating a reselection procedure to reselectto the first network 204.

Operation 530 can include determining presence of packet switched dataready for transmission from the wireless communication device 202 beforecompletion of the reselection procedure. By way of non-limiting example,operation 530 can include determining arrival at a cellular basebandlayer of packet switched data from a higher layer. Operation 540 caninclude holding the packet switched data at the wireless communicationdevice 202 at least until expiry of a reselection timer initiated duringthe reselection procedure. Operation 550 can include the wirelesscommunication device 202 determining whether a reselection criterion issatisfied after expiry of the reselection timer. In some instances, thedetermination of whether the reselection criterion is satisfied can bebased at least in part on a measurement and/or other evaluation of thefirst network 204 and/or a target cell thereof that can be performedduring a period of the reselection timer. In an instance in which it isdetermined at operation 550 that the reselection criterion has not beensatisfied, the method can proceed to operation 560, which can includethe wireless communication device 202 remaining on the legacy network206 and initiating transmission of the held packet switched data on thelegacy network 206. If, however, it is determined at operation 550 thatthe reselection criterion has been satisfied, the method can insteadproceed to operation 570, which can include the wireless communicationdevice 202 reselecting to the first network 204 and initiatingtransmission of the held packet switched data on the first network 204.

It will be appreciated that, in some example embodiments, there can befurther evaluation of the first network 204 and/or a target cell(s)thereof after performance of operation 550. As such, additionalreselection criteria can be evaluated following performance of operation550 in some such embodiments. In such embodiments, if a reselectioncriterion is not satisfied, the method can proceed to operation 560,rather than operation 570, even if the reselection criterion evaluatedin operation 550 is satisfied. In this regard, some example embodimentscan implement reselection procedures entailing evaluation of a series ofreselection criteria. If any individual reselection criterion in theseries is not met, then reselection to the first network 204 can beaborted, and transmission of the packet switched data can be initiatedon the legacy network 206.

In accordance with various example embodiments, packet switched data canbe held during a period of any reselection timer(s) that can beinitiated during a reselection procedure. In this regard, a reselectionprocedure that can be used to reselect to the first network 204 can varydepending on a type of the first network 204 and/or a type of the legacynetwork 206. Different reselection procedures can use a variety ofreselection timers. As such, it will be appreciated that packet switcheddata can be held for a period of any of one or more timers that can beapplied in accordance with a reselection procedure.

In some example embodiments, packet switched data can be held at leastuntil expiry of a timer that can be applied for determining whether atarget cell of the first network 204 is better than the serving cell ofthe legacy network 206. In example embodiments in which the firstnetwork 204 implements an LTE technology, such timer can be aTreselection timer, which can be used to measure a target LTE cell todetermine whether it is better than a serving cell of the legacy network206. The measurement can, for example, be performed based on criteriathat can be defined in a system information block (SIB), such as SIB 19.The wireless communication device 202 can, for example, determinewhether the target cell of the first network 204 satisfies reselectioncriteria for Treselection seconds before reselecting to the firstnetwork 204.

FIG. 6 illustrates a flowchart according to an example method forassisting return to the first network 204 from the legacy network 206after performance of a CSFB procedure by holding packet switched data atleast until expiry of a reselection timer applied for determiningwhether a target cell of the first network is better than the servingcell of the legacy network according to some example embodiments. Inthis regard, FIG. 6 illustrates operations that can be performed by thewireless communication device 202 in accordance with some exampleembodiments. One or more of processing circuitry 310, processor 312,memory 314, transceiver(s) 316, or selection control module 318 can, forexample, provide means for performing the operations illustrated in anddescribed with respect to FIG. 6. Operation 600 can include the wirelesscommunication device 202 participating in a CSFB procedure to transitionfrom the first network 204 to the legacy network 206 in response toinitiation of a voice call. Operation 610 can include the wirelesscommunication device 202 receiving a connection release from the legacynetwork 206 after termination of the voice call. After receiving theconnection release, the wireless communication device 202 can be in anRRC state other than CELL_DCH, such as CELL_FACH, CELL_PCH, URA_PCH,idle state, or other state which can allow the wireless communicationdevice 202 to reselect to the first network 204. Operation 620 caninclude the wireless communication device 202 initiating a reselectionprocedure to reselect to the first network 204.

Operation 630 can include determining presence of packet switched dataready for transmission from the wireless communication device 202 beforecompletion of the reselection procedure. By way of non-limiting example,operation 630 can include determining arrival at a cellular basebandlayer of packet switched data from a higher layer. Operation 640 caninclude holding the packet switched data at the wireless communicationdevice 202 at least until expiry of a reselection timer that can beapplied for determining whether a target cell of the first network 204is better than the serving cell of the legacy network 206. Operation 650can include the wireless communication device 202 determining whetherthe target cell of the first network 204 is better than the serving cellof the legacy network 206 after expiry of the reselection timer.Operation 650 can, for example, be performed based at least in part on ameasurement of the target cell of the first network 204 that can beperformed during a period of the reselection timer. In some exampleembodiments, operation 650 can include determining whether the targetcell of the first network 204 satisfies a reselection criterionindicating that it is better than the serving cell of the legacy network206 for a period of the reselection timer. In an instance in which it isdetermined at operation 650 that the target cell of the first network204 is not better than the serving cell of the legacy network 206, themethod can proceed to operation 660, which can include the wirelesscommunication device 202 remaining on the legacy network 206 andinitiating transmission of the held packet switched data on the legacynetwork 206. If, however, it is determined at operation 650 that thetarget cell of the first network 204 is better than the serving cell ofthe legacy network 206, the method can instead proceed to operation 670,which can include the wireless communication device 202 reselecting tothe first network 204 and initiating transmission of the held packetswitched data on the first network 204.

FIG. 7 illustrates a flowchart according to an example method forassisting return to an LTE network from a legacy network afterperformance of a CSFB procedure according to some example embodiments.In this regard, FIG. 7 illustrates an example embodiment of the methodof FIG. 6 in which packet switched data can be held at least untilexpiration of a Treselection timer when reselecting to an LTE network.One or more of processing circuitry 310, processor 312, memory 314,transceiver(s) 316, or selection control module 318 can, for example,provide means for performing the operations illustrated in and describedwith respect to FIG. 7. Operation 700 can include the wirelesscommunication device 202 participating in a CSFB procedure to transitionfrom an LTE network to a legacy network in response to initiation of avoice call. Operation 710 can include the wireless communication device202 receiving a connection release from the legacy network aftertermination of the voice call. After receiving the connection release,the wireless communication device 202 can be in an RRC state other thanCELL_DCH, such as CELL_FACH, CELL_PCH, URA_PCH, idle state, or otherstate which can allow the wireless communication device 202 to reselectto the LTE network. Operation 720 can include the wireless communicationdevice 202 initiating a reselection procedure to reselect to the LTEnetwork.

Operation 730 can include the wireless communication device 202 findinga best LTE cell on the LTE network. The best LTE cell can be selected asa target LTE cell for reselection. Operation 740 can include thewireless communication device 202 initiating the Treselection timer.Operation 750 can include determining presence of packet switched databefore expiry of Treselection timer. Operation 760 can include thewireless communication device 202 holding the packet switched data atthe wireless communication device at least until expiry of Treselectiontimer. At operation 770, the wireless communication device 202 candetermine whether the target LTE cell is better than the serving cell ofthe legacy network. Operation 770 can, for example, be performed basedat least in part on a measurement of the target LTE cell of that can beperformed during a period of the Treselection timer. In some exampleembodiments, operation 770 can include determining whether the targetLTE cell satisfies a reselection criterion indicating that it is betterthan the serving cell of the legacy network for the period of theTreselection timer.

In an instance in which it is determined at operation 770 that thetarget LTE cell is not better than the serving cell of the legacynetwork, the method can proceed to operation 780, which can include thewireless communication device 202 remaining on the legacy network andinitiating transmission of the held packet switched data on the legacynetwork. If, however, it is determined at operation 770 that the targetLTE cell is better than the serving cell of the legacy network, themethod can instead proceed to operation 790, which can include thewireless communication device 202 reselecting to the LTE network andinitiating transmission of the held packet switched data on the LTEnetwork.

As another example of a reselection timer for which packet switched datacan be held, in some example embodiments, if packet switched databecomes ready for transmission before expiry of a reselection timer thatcan be applied to allow measurement of a detected cell of the firstnetwork 204, the packet switched data can be held at least until expiryof the reselection timer to allow the wireless communication device 202to complete measurement of the detected cell of the first network 204.In example embodiments in which the first network 204 implements an LTEtechnology, such timer can be a T_(measureE-UTRA) timer, which canprovide a period for measuring a detected LTE cell(s) to determine ifthe detected LTE cell(s) satisfies an LTE reselection criterion.

FIG. 8 illustrates a flowchart according to an example method forassisting return to the first network 204 from the legacy network 206after performance of a CSFB procedure by holding packet switched data atleast until expiry of a reselection timer applied to allow measurementof a detected cell of the first network 204 according to some exampleembodiments. In this regard, FIG. 8 illustrates operations that can beperformed by the wireless communication device 202 in accordance withsome example embodiments. One or more of processing circuitry 310,processor 312, memory 314, transceiver(s) 316, or selection controlmodule 318 can, for example, provide means for performing the operationsillustrated in and described with respect to FIG. 8. Operation 800 caninclude the wireless communication device 202 participating in a CSFBprocedure to transition from the first network 204 to the legacy network206 in response to initiation of a voice call. Operation 810 can includethe wireless communication device 202 receiving a connection releasefrom the legacy network 206 after termination of the voice call. Afterreceiving the connection release, the wireless communication device 202can be in an RRC state other than CELL_DCH, such as CELL_FACH, CELL_PCH,URA_PCH, idle state, or other state which can allow the wirelesscommunication device 202 to reselect to the first network 204. Operation820 can include the wireless communication device 202 initiating areselection procedure to reselect to the first network 204.

Operation 830 can include determining presence of packet switched dataready for transmission from the wireless communication device 202 beforecompletion of the reselection procedure. By way of non-limiting example,operation 830 can include determining arrival at a cellular basebandlayer of packet switched data from a higher layer. Operation 840 caninclude holding the packet switched data at the wireless communicationdevice 202 at least until expiry of a reselection timer that can beapplied to allow measurement of a detected cell of the first network204. Operation 850 can include the wireless communication device 202determining whether a reselection criterion for reselecting to the firstnetwork 204 is satisfied after expiry of the reselection timer.Operation 850 can, for example, be performed based at least in part on ameasurement of the detected cell of the first network 204 that can beperformed during a period of the reselection timer. In an instance inwhich it is determined at operation 850 that the reselection criterionis not satisfied, the method can proceed to operation 860, which caninclude the wireless communication device 202 remaining on the legacynetwork 206 and initiating transmission of the held packet switched dataon the legacy network 206. If, however, it is determined at operation850 that the reselection criterion is satisfied, the method can insteadproceed to operation 870, which can include the wireless communicationdevice 202 reselecting to the first network 204 and initiatingtransmission of the held packet switched data on the first network 204.

FIG. 9 illustrates a flowchart according to an example method forassisting return to an LTE network from a legacy network afterperformance of a CSFB procedure according to some example embodiments.In this regard, FIG. 9 illustrates an example embodiment of the methodof FIG. 9 in which packet switched data can be held at least untilexpiration of a T_(measureE-UTRA) timer when reselecting to an LTEnetwork. One or more of processing circuitry 310, processor 312, memory314, transceiver(s) 316, or selection control module 318 can, forexample, provide means for performing the operations illustrated in anddescribed with respect to FIG. 9. Operation 900 can include the wirelesscommunication device 202 participating in a CSFB procedure to transitionfrom an LTE network to a legacy network in response to initiation of avoice call. Operation 910 can include the wireless communication device202 receiving a connection release from the legacy network aftertermination of the voice call. After receiving the connection release,the wireless communication device 202 can be in an RRC state other thanCELL_DCH, such as CELL_FACH, CELL_PCH, URA_PCH, idle state, or otherstate which can allow the wireless communication device 202 to reselectto the LTE network.

Operation 920 can include the wireless communication device 202initiating the T_(measureE-UTRA) timer, which can be used to measure oneor more LTE cells. Operation 920 can, for example, be performedattendant to performance of a reselection procedure for reselecting tothe LTE network. Operation 930 can include determining presence ofpacket switched data before expiry of T_(measureE-UTRA) timer. Operation940 can include the wireless communication device 202 holding the packetswitched data at the wireless communication device at least until expiryof T_(measureE-UTRA) timer. At operation 950, the wireless communicationdevice 202 can determine whether an LTE reselection criterion issatisfied. Operation 950 can, for example, be performed based at leastin part on a measurement of a detected LTE cell of that can be performedduring the period of the T_(measureE-UTRA) timer.

In an instance in which it is determined at operation 950 that the LTEreselection criterion is not satisfied, the method can proceed tooperation 960, which can include the wireless communication device 202remaining on the legacy network and initiating transmission of the heldpacket switched data on the legacy network. If, however, it isdetermined at operation 950 that the reselection criterion is satisfied,the method can instead proceed to operation 970, which can include thewireless communication device 202 reselecting to the LTE network andinitiating transmission of the held packet switched data on the LTEnetwork.

The various aspects, embodiments, implementations or features of thedescribed embodiments can be used separately or in any combination.Various aspects of the described embodiments can be implemented bysoftware, hardware or a combination of hardware and software. Thedescribed embodiments can also be embodied as computer readable code ona computer readable medium for controlling manufacturing operations oras computer readable code on a computer readable medium for controllinga manufacturing line. The computer readable medium is any data storagedevice that can store data which can thereafter be read by a computersystem. Examples of the computer readable medium include read-onlymemory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, andoptical data storage devices. The computer readable medium can also bedistributed over network-coupled computer systems so that the computerreadable code is stored and executed in a distributed fashion.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of specific embodimentsare presented for purposes of illustration and description. They are notintended to be exhaustive or to limit the described embodiments to theprecise forms disclosed. It will be apparent to one of ordinary skill inthe art that many modifications and variations are possible in view ofthe above teachings.

1. A method for assisting a wireless communication device to return toan LTE (Long Term Evolution) network from a legacy network, the methodcomprising: by the wireless communication device: receiving a connectionrelease from the legacy network after termination of a voice connection;initiating a reselection procedure to reselect to the LTE network inresponse to the connection release; holding pending uplink packetswitched data detected after initiating the reselection procedure atleast until expiry of a reselection timer; reselecting to the LTEnetwork after expiry of the reselection timer; and initiatingtransmission of the pending uplink packet switched data via the LTEnetwork after reselecting to the LTE network.
 2. The method of claim 1,further comprising: by the wireless communication device: determiningwhether a reselection criterion is satisfied after expiry of thereselection timer; wherein the reselecting to the LTE network and theinitiating transmission of the pending uplink packet switched data viathe LTE network are performed when the reselection criterion issatisfied; and wherein the method further comprises initiatingtransmission of the packet switched data via the legacy network when thereselection criterion is not satisfied.
 3. The method of claim 1,wherein the reselection timer comprises a reselection timer applied fordetermining whether a target LTE cell is better than a serving cell ofthe legacy network.
 4. The method of claim 3, further comprising: by thewireless communication device: determining, after expiry of thereselection timer, whether the target LTE cell is better than theserving cell of the legacy network; wherein the reselecting to the LTEnetwork and the initiating transmission of the pending uplink packetswitched data via the LTE network are performed when the target LTE cellis better than the serving cell of the legacy network; and wherein themethod further comprises initiating transmission of the pending uplinkpacket switched data via the legacy network when the target LTE cell isnot better than the serving cell of the legacy network.
 5. The method ofclaim 1, wherein the reselection timer comprises a reselection timerapplied to allow the wireless communication device to measure a detectedLTE cell.
 6. The method of claim 5, further comprising: determining,after expiry of the reselection timer, whether an LTE reselectioncriterion is satisfied based at least in part on measurement of thedetected LTE cell; wherein the reselecting to the LTE network and theinitiating transmission of the pending uplink packet switched data viathe LTE network are performed when the LTE reselection criterion issatisfied; and wherein the method further comprises initiatingtransmission of the pending packet switched data via the legacy networkwhen the LTE reselection criterion is not satisfied.
 7. The method ofclaim 1, further comprising: by the wireless communication device:determining presence of the pending uplink packet switched data at abaseband layer.
 8. The method of claim 1, wherein the wirelesscommunication device is in a radio resource control (RRC) state otherthan cell dedicated channel (CELL_DCH) state when the reselectionprocedure is initiated.
 9. A method for assisting a wirelesscommunication device to return to a first network from a second network,the method comprising: by the wireless communication device: receiving aconnection release from the second network after termination of a voiceconnection; initiating a reselection procedure to reselect to the firstnetwork after receipt of the connect release from the second network;holding pending uplink packet switched data detected after initiatingthe reselection procedure at least until expiry of a reselection timer;reselecting to the first network after expiry of the reselection timer;and initiating transmission of the pending uplink packet switched datavia the first network after reselecting to the first network.
 10. Themethod of claim 9, further comprising: by the wireless communicationdevice: determining whether a reselection criterion is satisfied afterexpiry of the reselection timer; wherein the reselecting to the firstnetwork and the initiating transmission of the pending uplink packetswitched data via the first network are performed when the reselectioncriterion is satisfied; and wherein the method further comprisesinitiating transmission of the pending uplink packet switched data viathe second network when the reselection criterion is not satisfied. 11.The method of claim 9, wherein the first network comprises a networkusing a Long Term Evolution (LTE) technology, and wherein the voiceconnection is handled by a circuit switched domain of the secondnetwork.
 12. A wireless communication device comprising: at least onetransceiver configurable to communicate with a first network and asecond network; and processing circuitry coupled to the at least onetransceiver and configured to control the wireless communication deviceto: receive a connection release from the second network aftertermination of a voice connection; initiate a reselection procedure toreselect to the first network after receipt of the connection release;hold pending uplink packet switched data detected after initiating thereselection procedure at least until expiry of a reselection timer;reselect to the first network after expiry of the reselection timer; andinitiate transmission of the pending uplink packet switched data via thefirst network after reselecting to the first network.
 13. The wirelesscommunication device of claim 12, wherein the processing circuitry isfurther configured to control the wireless communication device to:determine whether a reselection criterion is satisfied after expiry ofthe reselection timer; reselect to the first network and initiatetransmission of the pending uplink packet switched data on the firstnetwork when the reselection criterion is satisfied; and initiatetransmission of the pending uplink packet switched data on the secondnetwork when the reselection criterion is not satisfied.
 14. Thewireless communication device of claim 12, wherein the reselection timercomprises a reselection timer applied for determining whether a targetcell of the first network is better than a serving cell of the secondnetwork.
 15. The wireless communication device of claim 14, wherein theprocessing circuitry is further configured to control the wirelesscommunication device to: determine, after expiry of the reselectiontimer, whether the target cell of the first network is better than theserving cell of the second network; reselect to the first network andinitiate transmission of the pending uplink packet switched data via thefirst network when the target cell of the first network is better thanthe serving cell of the second network; and initiate transmission of thepending uplink packet switched data via the second network when thetarget cell of the first network is not better than the serving cell ofthe second network.
 16. The wireless communication device of claim 12,wherein the reselection timer comprises a reselection timer applied toallow the wireless communication device to measure a detected cell ofthe first network.
 17. The wireless communication device of claim 16,wherein the processing circuitry is further configured to control thewireless communication device to: determine, after expiry of thereselection timer, whether a reselection criterion for reselecting tothe first network is satisfied based at least in part on a measurementof the detected cell of the first network; reselect to the first networkand initiate transmission of the pending uplink packet switched data onthe first network when the reselection criterion is satisfied; andinitiate transmission of the pending uplink packet switched data on thesecond network when the reselection criterion is not satisfied.
 18. Thewireless communication device of claim 12, wherein the processingcircuitry is further configured to determine presence of pending uplinkpacket switched data at a baseband layer.
 19. The wireless communicationdevice of claim 12, wherein the wireless communication device is in acell forward access channel (CELL_FACH) state, a cell paging channel(CELL_PCH) state, a Universal Terrestrial Access Network (UTRA)registration area paging channel (URA_PCH) state, or an idle state whenthe reselection procedure is initiated.
 20. The wireless communicationdevice of claim 12, wherein the first network comprises a network usinga Long Term Evolution (LTE) technology, and wherein the voice callconnection is handled by a circuit switched domain of the secondnetwork.